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Heart Failure

Cardiac output insufficient for metabolic requirements of the body

Types:

Systolic dysfunction – decreased myocardial contractility

Diastolic dysfunction – insufficient expansion for ventricular volume

Problems accentuated by increased demand – high output heart failure

Forward failure: hypoperfusion

Backward failure:

congestion, eg hepatic congestion, pulmonary edema;

Raised ventricular end diastolic pressure(VEDP), increased venous pressure in RVF


CHF – Body’s Compensation

Tachycardia

Frank-Starling mechanism

increased End Diastolic Volume increases force of contraction
Compensated vs decompensated heart failure

Myocardial hypertrophy

Concentric hypertrophy in pressure overload, eg HTN, AS
Eccentric hypertrophy in volume overload eg AR, MR; heart will increase in size also
induction of fetal genes in the process makes the heart even more ineffective
Oxygen demand of the heart will be increased, making the matters worse.


Renin-angiotensin-aldosterone system
Secondary hyperaldosteronism causes a vicious cycle

Catecholamines – positive inotropic effect
Adrenergic redistribution of blood flow

Increase oxygen extraction from hemoglobin



Left-sided Heart Failure

Ischemic heart disease
Hypertension
Aortic and mitral valve disease
Myocardial disease, eg myocarditis and cardiomyopathy


Major causes of valvular diseases

Rheumatic heart disease
Infective endocarditis: acute valvular insufficiency( regurgitation)
Senile calcific aortic stenosis
Mitral valve prolpase syndrome
Dilated cardiomyopathy
MI causing papillary muscle dysfunction or rupture
Marfan syndrome causing aortic regurgitation
Rheumatoid arthritis
Syphilitic aortitis
Dissection of aorta( proximal or type A)


Lungs – Pulmonary edema

c/f (clinical features)

Dyspnea – breathlessness
Orthopnea – dyspnea lying down
Paroxysmal nocturnal dyspnea – extreme dyspnea
S3 gallop on auscultation, with pansystolic murmur of MR and basal crepitations in the lower lung fields- pt may be in AF

Morphology

Dilated left ventricle
Edematous and congested lungs
M/E of lungs:
transudate in alveoli
Septal edema
Alveolar hemorrhage
Heart failure cells: macrophages with engulfed hemosiderin
chronic congestion of lungs causes brown induration due to hemosiderin and fibrosis



Lung – alveolar hemorrhage, heme-filled
macrophages “heart failure cells”, with
iron stain to right

Kidneys – reduced perfusion

Ischemic tubular necrosis / ATN
Prerenal azotemia



Kidney -ATN


Brain in CHF – cerebral hypoxia

Irritability
Loss of attention span
Restlessness
Stupor
Coma


Right-sided heart failure

Pure cor pulmonale
Can be a Consequence of left-sided failure
Myocardial – myocarditis, cardiomyopathy, constrictive pericarditis
Left to right shunt

C/F(clinical features)

Raised JVP (jugular venous pressure)
Pedal edema
Tender hepatomegaly
Pleural effusion and Ascites




In this case, there is hypertrophy of the right ventricular myocardium.


Pulmonary arterial intimal thickening in pulmonary hypertension.


This is a plexiform lesion - a pulmonary artery which is dilated and has multiple small
recanalized lumens. This lesion is characteristic of very severe pulmonary hypertension.

Cor Pulmonale

Right ventricular hypertrophy and dilatation secondary to pulmonary hypertension
Acute - right ventricular dilatation following pulmonary embolism
Chronic - right ventricular hypertrophy


Causes of Cor pulmonale

Disorders Affecting Chest Movement

Kyphoscoliosis
Marked obesity (pickwickian syndrome)
Neuromuscular diseases

Disorders Inducing Pulmonary Arterial

Constriction
Metabolic acidosis
Hypoxemia
Chronic altitude sickness
Obstruction to major airways
Idiopathic alveolar hypoventilation


Right failure - systemic effects

Liver –
chronic passive congestion
Centrilobular necrosis of hepatocytes causing nutmeg appearance on gross feature
Cardiac cirrhosis
Spleen – congestive splenomegaly
Kidneys – congestion and hypoxia
Subcut – peripheral edema and anasarca
Pleural space – effusions
Brain – venous congestion and hypoxia
Portal - ascites




Liver – chronic passive congestion – blood pools near the central veins


Liver – chronic passive congestion – red cell pooling near central veins
and pericentral necrosis of the hepatocytes


CHF – final pathway to death

Ischemic heart disease
Hypertensive heart disease
Valvular heart disease
Cardiomyopathy
Myocarditis
Specific heart muscle diseases